Milesight UR35-L0GEU Industrial 4G Router with Serial and I/O

Milesight UR35-L0GEU industrial 4G router

The Milesight UR35-L0GEU is the entry-level model in the UR35 range: an industrial 4G LTE Cat 4 router with dual SIM failover, RS232 and RS485 serial ports, and isolated digital I/O. It reaches up to 150 Mbps download and 50 Mbps upload across EU LTE bands, with 3G and 2G fallback. This variant ships without Wi-Fi and without PoE output, so the front-panel module slot is unused. That keeps it the lowest-cost, serial-focused member of the family for cabinet, roadside, and remote telemetry sites. An NXP ARM Cortex-A7 processor and an IP30 metal enclosure rated from -40 to +70 C handle harsh installs, and an embedded Python SDK runs logic on the device.

Key features

• 4G LTE Cat 4: up to 150 Mbps download and 50 Mbps upload, with 3G and 2G fallback.
• Dual SIM: two Mini SIM (2FF) slots with automated failover between carriers, once configured in the web GUI.
• RS232 and RS485 serial: both ports on a 3.5 mm terminal block, 300 to 230400 bps, with Modbus gateway support.
• Isolated digital I/O: 1 dry-contact input and 1 wet-contact output for alarms, door contacts, and relay control.
• Five Ethernet ports: 1 WAN and 4 LAN at 10/100 Mbps, with 1.5 kV isolation.
• Industrial processor: NXP ARM Cortex-A7 at 528 MHz, 128 MB RAM, 128 MB flash, plus a microSD slot.
• Protocol support: Modbus RTU to TCP gateway, DLMS/COSEM client, MQTT, SNMP and TR069.
• VPN suite: OpenVPN, IPsec, WireGuard, ZeroTier, GRE, L2TP, PPTP and DMVPN.
• No Wi-Fi or PoE: this is the base build. Choose the -W variant for Wi-Fi or the -P variant for PoE output.
• Rugged build: IP30 metal housing, -40 to +70 C, 9 to 48 V DC input with surge and reverse polarity protection.

What is the UR35-L0GEU used for?

SCADA and industrial telemetry

The RS485 port and the Modbus RTU to TCP gateway connect PLCs, RTUs, and sensors to a central SCADA platform over cellular. Because the base variant carries the full serial and I/O set, it suits pump stations, compressor monitoring, and remote substation telemetry where wireless client access is not needed on site.

Smart metering and utility backhaul

The UR35 acts as a DLMS/COSEM client and speaks Modbus and MQTT, so it backhauls smart meter and grid data over the mobile network. Dual SIM failover keeps meter polling running when one carrier drops, which is a common requirement in AMI and substation metering.

Remote I/O and alarm signalling

The isolated digital input and output handle door contacts, tamper switches, and relay control. A change on the input can trigger an SMS, an email, or an MQTT publish, so an unattended site reports its state without a separate controller.

Serial device and legacy equipment backhaul

RS232 and RS485 in transparent mode connect older serial equipment to a modern IP network. Payment controllers, environmental loggers, and industrial instruments reach a head-end system over cellular without a protocol change at the device.

Backup WAN for fixed-line sites

Run a wired WAN as primary and let the UR35 fail over to cellular when the line drops. VRRP and link failover keep a branch, kiosk, or unattended site online during an outage.

Pro tip

The UR35-L0GEU is the serial and telemetry build, so the front-panel module slot is empty. There is no Wi-Fi and no GPS on this variant, and neither can be added by firmware. If you need local wireless access order the -W build, and if you need positioning order the -G build, because Wi-Fi and GPS share the same factory module slot. When wiring RS485, follow the Milesight convention: RXD to A, TXD to B. Reversing A and B is the most common cause of a silent Modbus link on first power-up, so check it before you suspect the config. Keep both cellular antennas fitted to the MAIN and AUX ports for reliable signal.

Building a resilient cellular connection

The UR35 carries two SIMs and switches automatically once failover is configured. For higher resilience, fit SIMs from two different networks and add a wired Ethernet WAN as a third path. The wide 9 to 48 V DC input lets you run the router from a small DC UPS, so a mains blip does not drop the link. Milesight Development Platform, gives you remote status, alerts, and firmware control across a fleet from one dashboard, and a fixed IP SIM on one slot enables inbound VPN access without carrier NAT in the way.

Which UR35 variant should I choose?

We stock four UR35 variants. They share the same cellular modem, serial ports, digital I/O, and RutOS-class software. They differ only on Wi-Fi and PoE. Prices exclude VAT.

• UR35-L0GEU (this page): no Wi-Fi, no PoE. The base serial and telemetry build.
• UR35-L0GEU-W: adds 2.4 GHz Wi-Fi, no PoE. For on-site wireless access or a Wi-Fi WAN path. In stock, 178.00.
• UR35-L0GEU-P: adds four 802.3af/at PoE output ports, no Wi-Fi. For powering IP cameras or access points from the LAN ports. In stock, 163.00.
• UR35-L0GEU-P-W: Wi-Fi and PoE together. The full-feature build. Available on back-order.

Frequently asked questions

Does the UR35-L0GEU have Wi-Fi?

No. This is the base variant with no Wi-Fi hardware. If you need local wireless access or a Wi-Fi WAN link, order the UR35-L0GEU-W, which fits an 802.11 b/g/n radio.

Does the UR35-L0GEU have PoE output?

No. There is no PoE PSE hardware on this variant, and PoE cannot be added by firmware. To power IP cameras or access points from the LAN ports, order the UR35-L0GEU-P, which supplies four 802.3af/at PoE ports.

Does this router have GPS?

No. The base variant has no GNSS module. On the UR35, GPS is a factory hardware option ordered as the -G build, and it shares the same module slot as Wi-Fi. If you need positioning, specify the -G build at order time.

What SIM card do I need for the UR35?

The UR35 takes two Mini SIM (2FF) cards for dual SIM failover. For remote management and inbound VPN, a fixed IP SIM is best because standard SIMs sit behind carrier NAT. See our fixed IP SIM cards and IoT SIM cards.

Can I run a VPN on the UR35?

Yes. The UR35 supports OpenVPN, IPsec, WireGuard, ZeroTier, GRE, L2TP, PPTP and DMVPN. See our guide to VPN on cellular routers for how to pick a tunnel type for remote access.

Does the UR35 support Modbus?

Yes. It works as a Modbus master or server and as a Modbus gateway, converting Modbus RTU on the serial port to Modbus TCP over the network. It also supports DLMS/COSEM and MQTT.

What is the operating temperature of the UR35?

The UR35 runs from -40 to +70 C. Cellular performance reduces above 60 C. Storage range is -40 to +85 C.

Related products and further reading

Browse the full range of Milesight industrial routers and our other Milesight 4G routers. For sites that need Wi-Fi or PoE, compare the UR35-L0GEU-W and the UR35-L0GEU-P. Pair the router with an external 4G antenna for cabinet installs, and choose the right IoT SIM card or fixed IP SIM for your deployment.